[gmx-developers] Problem with dihedral restraint in gromacs 4.6

[Landry Charlier]

Hello,

 From the manual page 133, the dihedral restraints want 4 atoms,  
funct=1, and 2 parameters (phi & dphi), i.e  ai   aj    ak    al   
funct  phi  dphi
But when I start grompp, I have the error message "Incorrect number of  
parameters - found 2, expected 3 or 6 for Dih. Rest.."
Is it a bug or dihedral restraints want a third parameter? which one,  
it's not pointed out neither in the manual nor in the webpage  
(http://www.gromacs.org/Documentation/How-tos/Dihedral_Restraints)

When I try with the dihedral restraints format of gromacs version  
4.5.4 - i.e   ai   aj    ak    al  type  label  phi  dphi  kfac  power
I have the same error message.
Incorrect number of parameters - found 5, expected 3 or 6 for Dih. Rest


It seems that grommp wants too many parameters. Indeed, it wants 3 or  
6 parameters whereas the correct format for gromacs4.6 needs 2  
parameters and the gromacs4.5.4 format needs 5 parameters.

Thank you

Landraille